The Unit Circle And Trigonometric Curves - Texas Instruments TI-80 Manual Book

The Unit Circle and Trigonometric Curves

You can use the parametric graphing feature of the TI.80 to show the
relationship between the unit circle and any trigonometric curve.
Problem
Procedure
Graph the unit circle and the sine curve to demonstrate
graphically the relationship between them.
Any function that can be plotted in function graphing can be
plotted in parametric graphing by defining the X component
as T and the Y component as F(T).
Following this procedure to solve the problem.
1. Press 3 and select
2. Press ) and set the Window variables.
TMIN = 0
TMAX = 2p
TSTEP = .1
3. Press ( and enter the expressions to define the unit
circle centered at (L1,0).
X1îT=COS Tì1
Enter the expressions to define the sine curve.
X2î=T
Turn off all other functions.
4. Press , to see the
unit circle.
Note: The "unwrapping" can be generalized. Replace
Y2î with any other trig function to "unwrap" that function.
,
RADIAN PARAM
XMIN = .2
XMAX = 2p
XSCL = pà2
Y1î=SIN T
Y2î=SIN T
function "unwrap" from the
SIN
, and .
SIMUL
YMIN = .3
YMAX = 3
YSCL = 1
SIN T
Applications 11-3
in